The lifter of the autogenous mill has dual purposes: first, it serves as a rock lifter, and second, as a carrier for withdrawal of the crashed fines. As a rock lifter, the angle of inclination of the lifter together with the speed of the mill should be so determined such that the crashing power or the crashing efficiency of the mill will be the maximum. While as a carrier for withdrawal of the crashed fines, same said angle of inclination together with same said speed of the mill should make the mean locus of the crashed fines pass through the center of the mill or the suction pipe. In my previous invention, the rock lifter and the carrier are the same; therefore, there is only one angle of inclination .beta. (FIG. 1). Since the mill has only one speed at any given instant, and the above two requirementsare so different to each other, it becomes evident that a single angle of inclination of the lifter could not fulfill both requirements at the same time.